AB0777 PERFORMANCE OF 2022 ACR/EULAR GPA, EGPA AND MPA CLASSIFICATION CRITERIA IN TURKISH VASCULITIS STUDY GROUP PROSPECTIVE COHORT (TRVAS)
Authors: E. C. Bolek, G. Ayan, E. Bilgin, E. Durak Ediboglu, E. Duran, R. C. Kardaş, T. Demirci Yildirim, B. Özdemir, T. S. Öğüt, M. Karabacak, O. Sadioglu Cagdas, R. Yildirim, E. Erpek, D. Ozgur, C. Akleylek, E. A. Acar, B. C. Uludogan, E. Unaldi, G. Sandal Uzun, Z. Özsoy, M. Ekici, B. Firlatan, G. S. Kart-Bayram, M. E. Kutu, M. Yalçin Mutlu, B. Armagan, O. Gercik, B. Bitik, H. Küçük, N. Yilmaz, N. S. Yasar Bilge, S. Çelik, L. Kiliç, T. Kaşifoğlu, A. Yazici, C. Bes, A. Erden, F. Erbasan, E. Asicioglu, F. Alibaz-Oner, A. Omma, A. Cefle, V. Yazisiz, M. A. Ozturk, H. Direskeneli, S. Kiraz, F. Onen, S. Akar, O. Karadag
Journal: Annals of the Rheumatic Diseases (2023)

<h3>Background</h3> External validation of the 2022 ACR/EULAR GPA, EGPA and MPA Classification Criteria is recommended by the DCVAS study group [1-3]. <h3>Objectives</h3> Turkish Vasculitis Study (TRVaS) prospective cohort is an electronic database including 15 centres from all over Turkey. We aimed to test performance of the recent criteria sets in TRVaS cohort. <h3>Methods</h3> Patients diagnosed according to physicians' decisions have been recruited prospectively in TRVaS (in total 3730 patients by January 2023). 2022 ACR/EULAR and 1990 ACR Classification Criteria sets were applied to all of the patients with AAV [GPA (n=533), EGPA (n=112), MPA (n=105), and unclassified AAV (n=70)], poliarteritis nodosa (PAN, n=47) and IgA Vasculitis (n=76). Performances were analysed using sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy. <h3>Results</h3> For the patients with GPA, 2022 criteria had higher sensitivity and specifity compared to 1990's (83.6% vs. 71.0% and 95.6% vs. 88.6%, respectively in Table). A significant increase was observed in sensitivity for 2022 criteria for patients with EGPA (86.4% vs.59.1%) with no change in specificity. Sensitivity and specificity of 2022 MPA criteria was calculated as 83.8% and 89.8%, respectively. Using the 2022 criteria to the patients with unclassified AAV, led to classify seven (10.0%) patients as GPA and 29 (41.0%) patients as MPA. Of 47 patients with PAN, one patient fulfilled 1990 ACR and another fulfilled 2022 GPA criteria. Others were not classified as EGPA or MPA. None of the patients with IgA vasculitis fulfilled 2022 AAV criteria. Of 533 patients with GPA, 1.5% fulfilled both 2022 GPA and MPA criteria and 7.7% fulfilled only MPA criteria (Figure). In each clinically diagnosed AAVs, around 10% of patients were not classified by any 2022 criteria. <h3>Conclusion</h3> Using 2022 ACR/EULAR Classification Criteria, improved sensitivity and specifity for GPA and sensitivity for EGPA were observed. Additionally, half of the unclassified AAV patients could be classified as either GPA or MPA. These criteria functioned well for the discrimination of patients with AAV from other small/medium vessel vasculitides such as PAN and IgA vasculitis. In total, over 80% of the patients with AAV were accordingly classified in paralel to the clinical diagnosis in each GPA/EGPA/MPA. <h3>References</h3> [1]Robson, J.C.et al s. <i>Ann Rheum Dis</i> 2022, <i>81</i>, 315-320. [2]Grayson, P.C. et al. <i>Ann Rheum Dis</i> 2022, <i>81</i>, 309-314. [3]Suppiah, R. <i>Ann Rheum Dis</i> 2022, <i>81</i>, 321-326. <h3>Acknowledgements:</h3> NIL. <h3>Disclosure of Interests</h3> None Declared.